Background: While laparoscopic surgical procedures have various advantages over traditional open techniques, artificial pneumoperitoneum is associated with severe bradycardia and cardiac arrest. Dexmedetomidine, an imidazole derivative that selectively binds to α2-receptors and has sedative and analgesic properties, can cause hypotension and bradycardia. Our primary aim was to assess the association between dexmedetomidine use and intraoperative bradycardia during laparoscopic cholecystectomy. Methods: We performed a systematic review with a meta-analysis and trial sequential analysis using the following PICOS: adult patients undergoing endotracheal intubation for laparoscopic cholecystectomy (P); intravenous dexmedetomidine before tracheal intubation (I); no intervention or placebo administration (C); intraoperative bradycardia (primary outcome), intraoperative hypotension, hemodynamics at intubation (systolic blood pressure, mean arterial pressure, heart rate), dose needed for induction of anesthesia, total anesthesia requirements (both hypnotics and opioids) throughout the procedure, and percentage of patients requiring postoperative analgesics and experiencing postoperative nausea and vomiting and/or shivering (O); randomized controlled trials (S). Results: Fifteen studies were included in the meta-analysis (980 patients). Compared to patients that did not receive dexmedetomidine, those who did had a higher risk of developing intraoperative bradycardia (RR: 2.81, 95% CI [1.34, 5.91]) and hypotension (1.66 [0.92,2.98]); however, they required a lower dose of intraoperative anesthetics and had a lower incidence of postoperative nausea and vomiting. In the trial sequential analysis for bradycardia, the cumulative z-score crossed the monitoring boundary for harm at the tenth trial. Conclusions Patients undergoing laparoscopic cholecystectomy who receive dexmedetomidine during tracheal intubation are more likely to develop intraoperative bradycardia and hypotension.

Background: Trial sequential analysis (TSA) is a recent cumulative meta-analysis method used to weigh type I and II errors and to estimate when the effect is large enough to be unaffected by further studies. The aim of this study was to illustrate possible TSA scenarios and their significance using meta-analyses published in the Korean Journal of Anesthesiology as working material. Methods: We performed a systematic medical literature search for meta-analyses published in the Korean Journal of Anesthesiology. TSA was performed on each main outcome, estimating the required sample size on the calculated effect size for the intervention, considering a type I error of 5% and a power of 90% or 99%. Results: Six meta-analyses with a total of ten main outcomes were included in the analysis. Seven TSAs confirmed the results of the meta-analyses. However, only three of them reached the required sample size. In the two TSAs, the cumulative z-lines were not statistically significant. One TSA boundary for effect was reached with the 90% analysis, but not with the 99% analysis. Conclusions In TSA, a meta-analysis pooled effect may be established to assess if the cumulative sample size is large enough. TSA can be used to add strength to the conclusions of meta-analyses; however, pre-registration of the TSA protocol is of paramount importance. This study could be useful to better understand the use of TSA as an additional statistical tool to improve meta-analysis quality.

Background: Trial sequential analysis (TSA) is a recent cumulative meta-analysis method used to weigh type I and II errors and to estimate when the effect is large enough to be unaffected by further studies. The aim of this study was to illustrate possible TSA scenarios and their significance using meta-analyses published in the Korean Journal of Anesthesiology as working material. Methods: We performed a systematic medical literature search for meta-analyses published in the Korean Journal of Anesthesiology. TSA was performed on each main outcome, estimating the required sample size on the calculated effect size for the intervention, considering a type I error of 5% and a power of 90% or 99%. Results: Six meta-analyses with a total of ten main outcomes were included in the analysis. Seven TSAs confirmed the results of the meta-analyses. However, only three of them reached the required sample size. In the two TSAs, the cumulative z-lines were not statistically significant. One TSA boundary for effect was reached with the 90% analysis, but not with the 99% analysis. Conclusions In TSA, a meta-analysis pooled effect may be established to assess if the cumulative sample size is large enough. TSA can be used to add strength to the conclusions of meta-analyses; however, pre-registration of the TSA protocol is of paramount importance. This study could be useful to better understand the use of TSA as an additional statistical tool to improve meta-analysis quality.

Background: Different regional anesthesia (RA) techniques have been used for laparoscopic cholecystectomy (LC), but there is no consensus on their comparative effectiveness. Our objective was to evaluate the effect of RA techniques on patients undergoing LC using a network meta-analysis approach. Methods: We conducted a systematic review and network meta-analysis. We searched PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, and Web of Science (Science and Social Science Citation Index) using the following PICOS criteria: (P) adult patients undergoing LC; (I) any RA single-shot technique with injection of local anesthetics; (C) placebo or no intervention; (O) postoperative opioid consumption expressed as morphine milligram equivalents (MME), rest pain at 12 h and 24 h post-operation, postoperative nausea and vomiting (PONV), length of stay; and (S) randomized controlled trials. Results: A total of 84 studies were included. With the exception of the rectus sheath block (P = 0.301), the RA techniques were superior to placebo at reducing opioid consumption. Regarding postoperative pain, the transversus abdominis plane (TAP) block (−1.80 on an 11-point pain scale) and erector spinae plane (ESP) block (−1.33 on an 11-point pain scale) were the most effective at 12 and 24 h. The TAP block was also associated with the greatest reduction in PONV. Conclusions RA techniques are effective at reducing intraoperative opioid use, postoperative pain, and PONV in patients undergoing LC. Patients benefit the most from the bilateral paravertebral, ESP, quadratus lumborum, and TAP blocks.